A newly proposed identification scheme which recognizes 10 different species within the genus Staphylococcus has been used to identify selected Clinical Center isolates. Once a sufficient number of organisms has been identified, the following questions may be answered: 1) What is the incidence of the various species in Clinical Center patients: 2) Is there any association between certain species and particular types of infections? 3) Is Staphylococcus saprophyticus an important cause of acute urinary tract infection in this hospital? 4) Are there significant differences in antibiotic susceptibilities among the different species? 5) Is speciation useful in determining contamination versus infection?